Question: $\overline{AC}$ is $12$ units long $\overline{BC}$ is $16$ units long $\overline{AB}$ is $20$ units long What is $\sec(\angle ABC)?$ $A$ $C$ $B$ $12$ $16$ $20$
Solution: $\sec(\angle ABC) = \dfrac{1}{\cos(\angle ABC)}$ How can we find $\cos(\angle ABC)$ SOH CAH TOA osine = djacent over ypotenuse Adjacent $= \overline{BC} = 16$ Hypotenuse $= \overline{AB} = 20$ $\cos(\angle ABC) = \dfrac{16}{20}$ $\sec(\angle ABC) = \dfrac{1}{\cos(\angle ABC)} = \dfrac{20}{16}$